We present crustal motion data obtained from an analysis of continuous and campaign GPS data for southern California and northern Baja Mexico, including the first results from a new six-station extension of the NSF EarthScope PBO network across the international border into northern Baja California, Mexico. This PBO extension was constructed in late Summer and early Fall 2010 in response to the April 4, 2010, Mw7.2 Sierra El Mayor-Cucapah earthquake. The locations of the six new PBO sites were selected in order to complement the dense existing continuous and campaign GPS networks in southern California, as well as providing needed continuous data for northern Mexico. Coseismic displacements for sites located nearest to the earthquake exceed 20 cm. In addition to allowing precise estimates of coseismic displacements, the ~17 years of pre-earthquake data for northern Baja California and southern California obtained from the archives at SCEC, UNAVCO, SOPAC, the University of Miami, and other sources, provides an opportunity to assess the evolution of postseismic deformation over the coming years. We will present updated results for pre- and post-seismic velocity for an assessment of post-seismic perturbations to the secular velocity field.